Regulated power supplies provide a stable direct current (DC) output voltage over a wide range of load conditions. Such regulated power supplies may incorporate a feedback circuit that samples the output voltage and provides the sampled output voltage to a pulse width modulator that varies a pulse train provided to a transformer and regulate the output voltage accordingly. Such feedback circuits require electrical isolation, which may be provided by devices such as optocouplers. However, use of optocouplers may not be feasible in all environments, such as space environments having high levels of radiation.